Many passengers, when falling asleep during a journey, tend to lean and bump their heads against the car side or car window. This may endanger them and cause lasting damage (headaches etc.) in the future. Using any known pillow (either inflated or not) is not successful because the pillow tends to slide down along the vertical surface. The present invention relates to an inflatable pillow for passengers which can be hung upon vertical surfaces (e.g. car windows) to improve passengers comfort.